Configuring Storm Control
This document describes how to configure Storm Control on the Cisco ASR 920 Series router.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Storm Control
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Port-level storm control should be configured on EVC interfaces.
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Storm control threshold value should be configured as CIR (bps, kbps, %).
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Applicable to all types of Storms (unicast, broadcast, and multicast).
Restrictions for Storm control
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Storm control is only enabled for ports with EVC configurations.
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Storm control is specific to the Layer2 physical interfaces and port-channels; It is not supported on the Layer 3 interfaces or BDI.
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Storm control is supported only for unknown unicast, broadcast, and unknown multicast ingress traffic; It is not supported for egress traffic.
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Port-level storm control is supported on the router. EFP-level storm control is not supported.
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Strom control on local connect and cross-connect is not supported.
Information on Storm Control
A storm occurs when huge amount of broadcast, multicast, or unicast packets flood the LAN, creating excessive traffic and degrading network performance. Errors in the protocol-stack implementation or in the network configuration can also cause a storm. The mechanism to prevent and control such events is known as storm control.
Storm Control monitors incoming traffic levels over a 1-second traffic storm control interval and, during the interval compares the traffic level with the traffic storm control level configured. The traffic storm control threshold level is a percentage of the total available bandwidth of the port. Each port has different storm control levels for broadcast, multicast, and unicast type of traffic.
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The rising threshold is the traffic limit after which, that particular traffic is blocked.
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The falling threshold is the traffic limit below which, that particular starts forwarding again, if it was already blocked.
![]() Note |
If a particular type of ingress traffic (unicast, broadcast and multicast) is more than the rising threshold configured on it, the interface goes to blocked state for that particular traffic. |
Storm control prevents traffic on a LAN from being disrupted by a broadcast, multicast, or unicast storm on a port. Storm control is applicable for physical interfaces and is used to restrict the unicast, broadcast and multicast ingress traffic on the Layer2 interfaces. The feature is disabled by default on the Cisco ASR 920 Series router.
Configuring Storm Control
Before you begin
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Configure the ports with EVC configuration.
Note
To disable Storm Control feature, use the no storm-control command.
SUMMARY STEPS
- enable
- configure terminal
- interface interface-id
- storm-control broadcast | multicast | unicast { level { rising_threshold falling_threshold | bps rising_threshold falling_threshold | pps rising_threshold falling_threshold } }
- storm-control action {shutdown | trap }
- exit
DETAILED STEPS
Command or Action | Purpose | |
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Step 1 |
enable Example:
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Enables privileged EXEC mode. Enter your password if prompted. |
Step 2 |
configure terminal Example:
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Enters global configuration mode. |
Step 3 |
interface interface-id Example:
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Specifies an interface type and enters interface configuration mode. |
Step 4 |
storm-control broadcast | multicast | unicast { level { rising_threshold falling_threshold | bps rising_threshold falling_threshold | pps rising_threshold falling_threshold } } Example:
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Specifies the global broadcast, multicast, or unicast storm control suppression level.
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Step 5 |
storm-control action {shutdown | trap } Example:
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Specifies the action to take when a storm occurs on a port
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Step 6 |
exit Example:
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Exits interface configuration mode and returns the router to global configuration mode. |
Configuration Example
interface GigabitEthernet0/0/1
no ip address
negotiation auto
storm-control broadcast level bps 50k 40k
storm-control multicast level pps 100 90
storm-control unicast level 1.00 0.50
service instance 1 ethernet
encapsulation dot1q 2
rewrite ingress tag pop 1 symmetric
bridge-domain 1
!
Verifying Storm Control
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Use the show storm-control command to verify the Storm Control feature configuration.
Router# show storm-control Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/0/0 Bcast Forwarding 0 pps 0 pps 0 pps Gi0/0/0 Ucast Forwarding 80.00% 20.00% 39.99% Gi0/0/1 Bcast Blocking 50k bps 40k bps 362.25k bps Gi0/0/1 Mcast Blocking 100 pps 90 pps 265 pps Gi0/0/1 Ucast Blocking 1.00% 0.50% 1.28%
Note
With each current traffic rate under display method, the storm control blocks traffic on the interface and the current traffic rate will always show 0%.
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Use the show storm-control command to display the storm control configurations for the configured storm type.
Router# show storm-control broadcast Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/0/2 Bcast Blocking 280k pps 260k pps 284.64k pps Te0/0/12 Bcast Blocking 2.29g bps 2g bps 2.49g bps Te0/0/13 Bcast Blocking 4.6m pps 4.3m pps 4.69m pps Po4 Bcast Link Down 45k pps 43k pps 0 pps Po5 Bcast Blocking 240k pps 235k pps 241.85k pps Router# Router#show storm-control unicast Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/0/2 Ucast Blocking 290k pps 280k pps 298.19k pps Te0/0/12 Ucast Blocking 4m pps 3.5m pps 4.74m pps Te0/0/13 Ucast Blocking 4.5m pps 4.3m pps 4.91m pps Po4 Ucast Link Down 45k pps 43k pps 0 pps Po5 Ucast Blocking 250k pps 240k pps 253.36k pps Router# Router#show storm-control multicast Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/0/2 Mcast Blocking 240m bps 220m bps 260.5m bps Te0/0/12 Mcast Blocking 2.25g bps 2g bps 2.38g bps Te0/0/13 Mcast Blocking 3g bps 2.5g bps 3.3g bps Po4 Mcast Link Down 45k pps 43k pps 0 pps Po5 Mcast Blocking 200k pps 190k pps 206.28k pps Router#
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Use the show storm-control GigabitEthernet command to verify the Storm Control feature configuration at the interface.
Router # show storm control GigabitEthernet 0/0/1 Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/0/1 Bcast Blocking 50k bps 40k bps 362.25k bps Gi0/0/1 Mcast Blocking 100 pps 90 pps 265 pps Gi0/0/1 Ucast Blocking 1.00% 0.50% 1.28%
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Use the show run interface command to verify the action trap configured on the port.
Router# show run interface GigabitEthernet 0/0/1 Building configuration... Current configuration : 300 bytes ! interface GigabitEthernet0/0/1 no ip address negotiation auto storm-control broadcast level 9.00 7.00 storm-control action trap service instance trunk 1 ethernet encapsulation dot1q 1-200 rewrite ingress tag pop 1 symmetric bridge-domain from-encapsulation ! end
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The following example shows the action trap being sent when a storm is hit.
Router# show storm-control G 0/0/1 Interface Type Filter State Upper Lower Current --------- ------ ------------- ----------- ----------- ---------- Gi0/4/2 Bcast Blocking 9.00% 7.00% 11.00% May 29 14:46:28.008 IST: %STORM_CONTROL-3-TRAP: A packet storm was detected on Gi0/4/2. Sending SNMP trap
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The following example shows the action shutdown configured.
Router# show run interface Gi0/0/1 Building configuration... Current configuration : 300 bytes ! interface GigabitEthernet0/0/1 no ip address negotiation auto storm-control broadcast level 9.00 7.00 storm-control action shutdown service instance trunk 1 ethernet encapsulation dot1q 1-200 rewrite ingress tag pop 1 symmetric bridge-domain from-encapsulation ! end
Additional References
Related Documents
Related Topic | Document Title |
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Cisco IOS commands |
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mcl/allreleasemcl/all-book.html |
Standards and RFCs
Standard/RFC | Title |
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No specific Standards and RFCs are supported by the features in this document. |
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MIBs
MIB | MIBs Link |
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— |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
Description | Link |
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The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Feature Information for Storm Control
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
Storm Control |
Cisco IOS XE Release 3.13.0S |
This feature was introduced on the Cisco ASR 920 Series Aggregation Services Router (ASR-920-12CZ-A, ASR-920-12CZ-D, ASR-920-4SZ-A, ASR-920-4SZ-D). |
Feature Name |
Releases |
Feature Information |
Cisco IOS XE Release 3.14.0S |
This feature was introduced on the Cisco ASR 920 Series Aggregation Services Router (ASR-920-12CZ-A, ASR-920-12CZ-D, ASR-920-4SZ-A, ASR-920-4SZ-D, ASR-920-10SZ-PD, ASR-920-24SZ-IM, ASR-920-24SZ-M, ASR-920-24TZ-M) . |